PeachParts Mercedes-Benz Forum - 1996 S320 Head Unit Replacement Options

I am looking for a replacement 1 DIN stereo unit that will work with my existing audio installation (factory premium). Ideally, I am looking for a CD/Stereo with additional inputs. My understanding is it needs to be 2Ohm.

The car is a 1996 S320 LWB with a premium 11 speaker system. I have been told that if I want to put in one of these new Pioneer DEH7000BT Bluetooth MP3 style head units, I will need to replace the amplifier, all speakers, and all wiring. Is this true? If so, what are my alternatives to get the features that these new units offer? I do have a Sirius S50 attached as well, that I would hope to keep.

Thanks for your wisdom.